During the storage of sugar beets (Beta vulgaris), i.e., during the period between harvest and further processing, significant saccharose losses occur, which can be attributed mainly to respiration and the saccharose metabolism. The saccharose loss is associated with a reduction in the quality of the sugar beets, as the content of reducing sugars, such as glucose and fructose, increases (Burba, M., Zeitschrift für die Zuckerindustrie, 26 (1976), 647–658). The saccharose breakdown during the storage of sugar beets comprises as a first metabolic step an enzymatic hydrolysis as a result of a vacuolar invertase. Vacuolar and/or cell wall-bound invertase isoforms are also induced by de novo injuries to beet tissue (Milling et al., J. Exp. Bot., 44 (1993), 1687–1694). This means that injuries also result in a saccharose hydrolysis, particularly in order to provide hexoses necessary for wound respiration and the wound-activated oxidative pentaphosphate (OPP) cycle. A precise analysis as to which invertase isoforms are involved in the wound reaction has not been performed, however. Understanding the regulation and the role of the individual invertase isoforms in the injured sugar beet tissue is critical, however, for being able to manipulate the expression of the individual isoforms, especially considering the substantial saccharose losses during the storage period.